Portable air moving apparatuses have been used for many years to cool and heat a specific area. The ability to confine the effects of the device to the specific area in which the user is located compared to the need to heat or cool an entire building results in saving energy.
Conventional portable air moving apparatuses commonly locate the impeller proximate the air outlet of the device. If the apparatus is used for heating, the additional components, such as the heating element, are also located near the heated air outlet of the device. These conventional structures are designed to accomplish an efficient and direct flow of air from the impeller and to immediately expel the air from the device. In an effort to achieve air flow efficiency, conventional air moving apparatus require that the housing shape and form located proximate the air outlet be of sufficient size to enclose the impeller and/or heating element. Additional structures, such as motor mountings, scroll housings (used with centrifugal impellers), air guides and air cut-offs (used with transverse impellers), for example, further increase the required housing dimension necessary to accommodate the proximate location relationship between the impeller, heating element, air outlet and other components.
One disadvantage of conventional portable air moving apparatus is that the required size of the housing near the air exit impedes the ability of the device to entrain ambient air into the generated air stream. For example, entrainment of ambient air into a heated air stream as it exits the device would have an effect of increasing the overall temperature of a greater quantity of air in a room. In effect, such a device would more directly accomplish the goal of space heater use. This goal is, to some extent, impeded by the structure of conventional space heaters.
Additionally, a conventional portable air moving device utilized to heat the air requires specific and/or carefully controlled air flow characteristics. This is needed to assure that the air flow is heated properly as it passes through the heating element. Such air flow characteristics include, for example, air velocities, air volumes, and the like. As such, the proximity of the impeller relative to the heating element and the desire of locating the heating element immediately proximate the air outlet limits the ability of the device to have multiple heated air outlets. Each of said air outlets would require a discrete heating element and possibly a discrete impeller. The additional parts within the structure increase the cost and complexity of the devise.